Painting over painted wallpaper

[stealthwolf]

The main bedroom has been lined with paper and then painted on three walls. The fourth wall has had patterned dark blue wallpaper. The wall opposite has been painted dark blue. The other two walls have been painted white. The dark colours are depressing me.

I want to repaint the whole room to a uniform light colour eg cream, beige, white etc (haven't decided yet).

Can I just paint over the previous paint?
Do I need to do any prep work?
Any particular hints or tips (especially for someone who has never painted except art classes at school)?
Would it be better to just strip the wallpaper? I've no idea what's underneath.

 

[Robbie uk]

If the wallpaper is sound and not lifting anywhere, just go straight over with your top coats of your chosen colour, finish etc. You may need more coats on the darker walls.

 

[stealthwolf]

If the wallpaper is sound and not lifting anywhere

The wallpaper itself is fine and in excellent condition. Just the wrong colour. Do I need to clean the surface in any way before painting?

 

[Robbie uk]

You shouldnt need too , maybe a dust over but nothing else.

 

[stealthwolf]

Thanks for your advice @Robbie uk

 

[Tigercubrider]

Get some high opacity emulsion from screwfix or similar u